code: def verify_optional_callable(var_name: str, var):
      if var and not callable(var):
          raise TypeError(
              "{} must be a callable (was {})".format(
                  var_name, type(var)
              )
          )
  
imports: import base64
  import logging
  import os
  from glob import glob
  from io import IOBase
  from typing import Iterable, List, Mapping, Optional, Set, TypeVar, Union
  from neptune.internal.types.stringify_value import StringifyValue
label_desc: Use image node_id 14 for calling a global function with example usage: verify_optional_callable(var_name, var) without return types